For shipment or storage, packages are frequently wrapped with a plastic film material so as to provide a strong and protective layer about the package. By "package" is meant here any object or article, or collection of objects or articles, which are to be wrapped such as for shipment or storage. One common approach is to position the package on a rotating platform and dispense the plastic film in engagement with the package as the package is rotated. The plastic film dispenser may be either hand-held or attached to the package wrapping apparatus.
Referring to FIGS. 1a and 1b, there are respectively shown partially cutaway and partially in phantom top plan and side elevation views of a typical prior art package wrapping apparatus 100. The wrapping apparatus 100 includes a rotating deck 102 which is disposed upon and supported by a plurality of rollers 104a-104d. The package to be wrapped is disposed on the rotating deck 102 which may also support a pallet on which the package is disposed for ease of handling the package. Each of these support rollers 104a-104d is attached to and supported by a respective bracket 106a-106d. A center, lower portion of the rotating deck 102 is positioned on and supported by a combination of a support shaft 112, bearings 116 and a race 114. The combination of rollers 104a-104d and bearings 116 allow for the free rotation of deck 102 about a generally vertical axis through shaft 112. A rotary drive arrangement 108 such as including an electric motor is typically coupled to the support shaft 112 by means of sprockets or pulleys and a chain, belt, or other suitable linkage 110.
One disadvantage of the prior art package wrapping apparatus 100 is that the tension of the wrapping material is difficult to control and thus the tightness of the wrap about the package is generally nonuniform. In addition, the rotational drive arrangement does not provide positive control over the rotating package thus necessitating the use of a brake mechanism to slow down and stop the rotating deck and package combination. Finally, the rollers 104a-104d disposed about and engaging a lower portion of the rotating deck 102 must be precisely aligned relative to one another as well as to the deck and substantially increase the cost and complexity of the wrapping apparatus.
The present invention provides a winch with a locking mechanism which is easily manipulated using only one hand between a locked mode and an unlocked mode in which a cable, rope or chain may be wound onto the winch or may be withdrawn from the winch.